<!--
  speedy-vision.js
  GPU-accelerated Computer Vision for JavaScript
  Copyright 2020-2024 Alexandre Martins <alemartf(at)gmail.com>

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

  greyscale-video.html
  Convert a video to greyscale
-->
<!doctype html>
<html>
    <head>
        <meta charset="utf-8">
        <meta name="description" content="speedy-vision.js: GPU-accelerated Computer Vision for JavaScript">
        <meta name="author" content="Alexandre Martins">
        <title>Convert video to greyscale</title>
        <link href="demo-base.css" rel="stylesheet">
        <script src="demo-base.js"></script>
        <script src="../dist/speedy-vision.js"></script>
    </head>
    <body>
        <h1>Convert video to greyscale</h1>
        <div>
            <span id="status"></span>
            <canvas id="canvas-demo"></canvas>
        </div>
        <video id="video"
            poster="../assets/loading.jpg"
            loop muted autoplay playsinline
            title="Free video by Cinema Professionals, https://www.pexels.com/pt-br/video/assistindo-a-aguia-voar-3635378/">
                <source src="../assets/flying-eagle.webm" type="video/webm" />
                <source src="../assets/flying-eagle.mp4" type="video/mp4" />
        </video>
        <script>
window.onload = async function()
{
    /*

    This is our pipeline:

    Image  ---> Convert to ---> Image
    Source      greyscale       Sink

    */

    // Load a video
    const video = document.getElementById('video');
    const media = await Speedy.load(video);

    // Setup the pipeline
    const pipeline = Speedy.Pipeline(); // create the pipeline and the nodes
    const source = Speedy.Image.Source();
    const sink = Speedy.Image.Sink();
    const greyscale = Speedy.Filter.Greyscale();

    source.media = media; // set the media source

    source.output().connectTo(greyscale.input()); // connect the nodes
    greyscale.output().connectTo(sink.input());

    pipeline.init(source, sink, greyscale); // add the nodes to the pipeline

    // Main loop
    (function() {
        const canvas = setupCanvas('canvas-demo', media.width, media.height, video.title);
        let image = null, frameReady = false;

        async function update()
        {
            const result = await pipeline.run();
            image = result.image;

            frameReady = true;
            setTimeout(update, 1000 / 60);
        }
        update();

        function render()
        {
            if(frameReady) {
                renderMedia(image, canvas);
            }

            frameReady = false;
            requestAnimationFrame(render);
        }
        render();

        setInterval(renderStatus, 200);
    })();
}
        </script>
        <section id="speedy-vision">
            <span>Powered by <a href="https://github.com/alemart/speedy-vision" target="_blank">speedy-vision.js</a></span>
            <a href="https://github.com/sponsors/alemart" target="_blank" class="button">
                <img alt="GitHub Sponsors" src="https://img.shields.io/github/sponsors/alemart?style=for-the-badge&logo=github&label=Sponsor&labelColor=royalblue&color=gold">
            </a>
        </section>
    </body>
</html>
